Highly spontaneous spin polarization engineering of single-atom artificial antioxidases towards efficient ROS elimination and tissue regeneration

Abstract

Creating atomic catalytic centers has emerged as a conducive path to design efficient nanobiocatalysts to serve as artificial antioxidases (AAOs) that can mimic the function of natural antioxidases to scavenge noxious reactive oxygen species (ROS) for protecting stem cells and promoting tissue regeneration. However, the fundamental mechanisms of diverse single-atom sites for ROS biocatalysis remain ambiguous. Herein, we disclose that the highly spontaneous spin polarization mediates the profound origin of H2O2-elimination activities in engineering ferromagnetic elements (Fe, Co, Ni)-based AAOs with atomic centers. The experimental and theoretical results reveal that the Fe-AAO exhibits the most excellent catalase-like kinetics and turnover number, while the Co-AAO shows the highest glutathione peroxidase-like activity and turnover number. Furthermore, our investigations prove that both the Fe-AAO and Co-AAO can effectively secure the functions of stem cells in high ROS microenvironments and promote injured tendon tissue repair by scavenging the H2O2 and other ROS. We believe that the proposed highly spontaneous spin polarization engineering of ferromagnetic element-based AAOs will provide essential guidance and practical opportunities for developing efficient AAOs with eliminating ROS, protecting stem cells, and accelerating tissue regeneration.